Honestants and Swindlecants III.

[rookie1ja]

Honestants and Swindlecants III. - Back to the Logic Problems

Our gringo displeased the sovereign with his intrusive questions and was condemned to death. But there was also a chance to save himself by solving the following logic problem. The gringo was shown two doors - one leading to a scaffold and the second one to freedom (both doors were the same) and only the door guards knew what was behind the doors. The sovereign let the gringo put one question to one guard. And because the sovereign was an honest man he warned that exactly one guard is a Swindlecant.

What question can save the gringo's life?

Classic wording:

Two Doors

You are travelling down a country lane to a distant village. You reach a fork in the road and find a pair of identical twin sisters standing there. One of the sisters always tells the truth and the other always lies.

If you are allowed to ask only one question to one of the sisters to find the correct road to the village, what is your question?

This old topic is locked since it was answered many times. You can check solution in the Spoiler below.

Pls visit New Puzzles section to see always fresh brain teasers.

Honestants and Swindlecants III. - solution

There are a few types of questions:

Indirect question: „Hey you, what would the other guard say, if I asked him where this door leads?“ The answer is always negated.


Tricky question: „Hey you, does an honestant stand at the door to freedom?“ The answer will be YES, if I am asking an honestant who is standing at the door to freedom, or if I am asking a swindlecant standing again at the same door. So I can walk through the door. A similar deduction can be made for negative answer.

Complicated question: „Hey you, what would you say, if I asked you ...?“ An honestant is clear, but a swindlecant should lie. However, he is forced by the question to lie two times and thus speak the truth.

[Guest]

Tricky question: „Hey you, does an honestant stand at the door to freedom?“ The answer will be YES, if I am asking an honestant who is standing at the door to freedom, or if I am asking a swindlecant standing again at the same door. So I can walk through the door. A similar deduction can be made for negative answer. I dont understand how this question works... unless you explain that the honest one stands at the door to freedom...

[rookie1ja]

Tricky question: „Hey you, does an honestant stand at the door to freedom?“ The answer will be YES, if I am asking an honestant who is standing at the door to freedom, or if I am asking a swindlecant standing again at the same door. So I can walk through the door. A similar deduction can be made for negative answer. I dont understand how this question works... unless you explain that the honest one stands at the door to freedom...

If the answer is YES:

Only honestant standing at the freedom door or swindlecant staying at the freedom door can say it.

So you go through that door.

If the answer is NO:

Only honestant standing at the wrong door or swindlecant staying at the wrong door can say it.

So you go through the other door.

[Guest]

The Indirect question is the simplest in my mind (I came up with that solution a long time ago). I think it's also the original solution, and I know it's the one given in The Labyrinth. I think I've come up with the Complicated question on my own, but I'm not sure about that. Either way, it would work.

I hadn't ever heard of the Tricky question, so I had to figure it out. After some fiddling, I came up with this:

---Freedom-------Death

1. H=Yes----------S=No

2. S=Yes----------H=No

You have the freedom door on the left and the death door on the right. In scenario 1, the Honestant (H) stands in front of the freedom door, and the Swindlecant (S) stands in front of the death door. Since the true answer to the question is "yes", the Honestant will answer "yes" and the Swindlecant will answer "no".

In scenario 2, the roles are reversed. Since the correct answer is "no", the Swindlecant will say "yes" and the Honestant will say "no". As you can see from the chart, the only way either one can say "yes" is if they are standing in front of the Freedom door, and the only way either one can say "no" is if they are not.

This is exactly what you said, but I added a visual example for reference (that's what it took for me to figure it out to begin with).

[Guest]

Yoo, new here, isn't the simplest question: "Do you know what is behind your door?"

If it was already posted, sorry wasn't very thorough in reading the other posts...

[Guest]

I don't think that would work. It would tell you who was who, but wouldn't tell you which door is which.

[Guest]

What if you asked a guard "Which door would the other guard would want me to pick?"

The honestant guard would point to the door leading to the scaffold; and the Swindlecant would point to the same door, but that is assuming that the honestant doesn't want to see you die.

[Guest]

What if you asked a guard "Which door would the other guard would want me to pick?"

The honestant guard would point to the door leading to the scaffold; and the Swindlecant would point to the same door, but that is assuming that the honestant doesn't want to see you die.

Fenix, that's the indirect question, only you said it in plainer English

[Guest]

Now doesn't this remind you of that old short-story called "The Lady or the Tiger?"

The only answer I can understand would be the indirect question (I saw that several weeks ago on NUMB3RS as well, for those of you who watch it).

Numenor

[Guest]

The indirect question makes sense and I agree with it.

The Tricky question logic looks flawed to me, unless I am missing something. the question asked is 'Hey you, does an honestant stand at the door to freedom' Whilst your conclusions are correct as to the answers you will get, nothing actually indicates whether you are talking to an honestant or a swindlecant, So the conclusion you draw is that a honestant is standing in front of the door to freedom, but you still don't know which of the 2 is the honestant.

Is it me?

[Guest]

I think that the following part is misleading:

"he warned that one guard is a Swindlecant"

because that definitely means that there is one guard who is a swindlecant, but what about the other guard? To me, the other guard could easily be either a swindlecant or an honestant with the above phrase still being correct.

[Guest]

The indirect question makes sense and I agree with it.

The Tricky question logic looks flawed to me, unless I am missing something. the question asked is 'Hey you, does an honestant stand at the door to freedom' Whilst your conclusions are correct as to the answers you will get, nothing actually indicates whether you are talking to an honestant or a swindlecant, So the conclusion you draw is that a honestant is standing in front of the door to freedom, but you still don't know which of the 2 is the honestant.

Is it me?

I was having the same problem... but it makes sense now, rookie1ja's second response clears it up if you read it carefully...

I'll try to explain it with what cleared it up for me (specifics ).

Let's say Door 1 leads to freedom and Door 2 to scaffolding:

You ask the guy in front of Door 1 if an honestant stands in front of the door to freedom:

If he's an honestant, he'll say yes, because an honestant does.

If he's a swindlecant, he'll lie and say yes (an honestant does), when, really, a swindlecant does.

If the Doors are swapped, and 1 leads to scaffolding and 2 to freedom and you ask the guy in front of Door 1 the same question:

If he's an honestant, he'll say no, because a swindlecant does.

If he's a swindlecant, he'll say no, because an honestant does.

So if he says yes, go through his door, if he says no, go through the other door.

Does that help?

[Guest]

I think that the following part is misleading:

"he warned that one guard is a Swindlecant"

because that definitely means that there is one guard who is a swindlecant, but what about the other guard? To me, the other guard could easily be either a swindlecant or an honestant with the above phrase still being correct.

This was the same problem I ran into. If you note that both guards can be swindlecants or one of each then there is no single question that can solve this problem.

[Guest]

I think that the following part is misleading:

"he warned that one guard is a Swindlecant"

because that definitely means that there is one guard who is a swindlecant, but what about the other guard? To me, the other guard could easily be either a swindlecant or an honestant with the above phrase still being correct.

This was the same problem I ran into. If you note that both guards can be swindlecants or one of each then there is no single question that can solve this problem.

I didn't even think of that, but I went back and read the question again and it is misquoted above (unless the admin changed it since) as it now reads: "he warned that exactly one guard is a Swindlecant".

[Guest]

Didn't anyone see Labryinth??? The same question was used in that movie...

Sarah (Jennifer Connelly) is standing in front of two guards, each guarding a door. One of them "always tells the truth" and one of the "always lies"...

Sarah: "Would he tell me that this door leads to the castle?"

Guard 1: "Yes?"

Sarah: "Then the other door leads to the castle and this door leads to certain death."

Guard 1: "How do you know? He could be telling the truth!"

Sarah: "But then you wouldn't be."

Guard 1: "But I keep telling the truth!"

Sarah: "Then he would be lying."

Guard 1: "Is that right?"

Guard 2: "I don't know, I've never understood it!"

Great flick. Gotta love Jim Henson.

[Guest]

i would ask the guard " which door led to scaffold" In case the guard was Honestant, he would point the correct door. Thus i would go to the other. if the guard was a Swindlecant, known to always lie, then he would lead me to the door of freedom..... I think......

[Guest]

My first reply was pretty stupid. here is another shot at it. As the guard " if you were in my shoes which door would you choose. This is not true or false question. So even a swindlecants would answer correctly..... hope this is better...

[Guest]

My first reply was pretty stupid. here is another shot at it. As the guard " if you were in my shoes which door would you choose. This is not true or false question. So even a swindlecants would answer correctly..... hope this is better...

sorry tommy, it doesn't matter if the question is a 'true or false'. the swindlecant would still lie, the honestant would still be truthful. the swindlecant would in fact tell you which door he would not choose, while the honestant would tell you which door he would choose. this question would be of no assistance in determining either who was who or which door was which.

[Guest]

I'm assuming there's exactly one Swindlecant, and both know which is the freedom door.

Say freedom is behind door #1. Ask either guard the following question: "Which door would the other guard tell me leads to freedom?"

If you happened to ask the Honestant, he would truthfully tell you that the other guard (the Swindlecant) would tell you door #2 leads to freedom. If you happened to ask the Swindlecant, he would dishonestly tell you that the other guard (the Honestant) would tell you that door #2 leads to freedom.

So it doesn't matter which one you happen to ask. Since both guards are "involved" in the answer, either guard will tell you the other would say freedom is behind door #2. Therefore it is REALLY behind door #1.

[Guest]

I think that the following part is misleading:

"he warned that one guard is a Swindlecant"

because that definitely means that there is one guard who is a swindlecant, but what about the other guard? To me, the other guard could easily be either a swindlecant or an honestant with the above phrase still being correct.

This was the same problem I ran into. If you note that both guards can be swindlecants or one of each then there is no single question that can solve this problem.

That's why I always liked the so-called Complicated Question. It doesn't matter if there is one guard or five. It doesn't matter if zero or all of them are Swindlecants. It doesn't matter if the person who told you about the Swindlecants is a Swindlecant himself.

I think the only reason that the Indirect Question seems more obvious to most people is because they assume they were given two guards for a reason.

[Guest]

You all are making this waaay too complicated. I would ask the guard, either one (it does not matter which), which door he/she would prefer to walk through if he/she were in my shoes. There was only one person that replied that agrees with me on this. Everyone wants to live, even if you are a liar.

[Guest]

You all are making this waaay too complicated. I would ask the guard, either one (it does not matter which), which door he/she would prefer to walk through if he/she were in my shoes. There was only one person that replied that agrees with me on this. Everyone wants to live, even if you are a liar.

And what are you to do if the guard you ask answers "I'd pick the door on the left"?

[Guest]

You all are making this waaay too complicated. I would ask the guard, either one (it does not matter which), which door he/she would prefer to walk through if he/she were in my shoes. There was only one person that replied that agrees with me on this. Everyone wants to live, even if you are a liar.

If you asked the honestant, he would give you the right door. If you asked the swindlecat, he'd give you the wrong one. That works except for one tiny detail.... you don't know which is a swindlecat and which is an honestant. Therefore you would not know whether the guard you asked was pointing to the right or wrong door. Which basically means you're no better off than you were before. In fact, that method is entirely random. Well, at least you'd have a 50% chance.... but I wouldn't count on my luck.

[Guest]

My brother-in-law asked me a similar riddle years ago.

You have recently died, and instead of ascending into Heaven or Purgatory, you find yourself standing in front of two doors. In front of each door stands a guard. Both guards are identical-looking, as both doors are identical-looking. A voice speaks to you from out of nowhere informing you that one door leads to Heaven, and the other door leads to Hell. One guard always tells the truth, and one guard always lies. You must determine which door is which, and which guard is which, but you are allowed to only ask one question to one guard and it must pertain to the doors.

What question do you ask one of the guards?

Compare that riddle to the original one posted here...

Our gringo displeased the sovereign with his intrusive questions and was condemned to death. But there was also a chance to save himself by solving the following logic problem. The gringo was shown two doors - one leading to a scaffold and the second one to freedom (both doors were the same) and only the door guards knew what was behind the doors. The sovereign let the gringo put one question to one guard. And because the sovereign was an honest man he warned that exactly one guard is a Swindlecant.

What question can save the gringo's life?

The answer is simple. You walk up to either guard (doesn't matter which) and you ask the following question - "If I were to ask the other guard which door leads to freedom, which door would he point to?", then you take the opposite door. Here's why.

Suppose the guard on the left is the Honestant, and he stands in front of the door that leads to freedom. Mind you, you don't know which guard is which, nor which door is which. You ask him which door the other guard (presuming the other is the Swindlecant) would point to that leads to freedom, the Honestant would tell you the other guard would point to the door on the right, which, of course, is a lie - that door leads to the scaffold. Likewise, suppose the guard on the left is the Swindlecant, and the door he stands in front of is the door to freedom. You ask him which door would the other guard point to, and he would tell you the other guard would point to the door on the right - again, that's a lie because the Honestant would tell you otherwise.

Now let's reverse it. Suppose the guard on the right is the Honestant, and the door he stands in front of is the door to the scaffold. You ask the question - he'd tell you the other guard would point to the door on the right - an outright lie on the other guard's part.

Regardless of the answer you're told, always take the opposite door.

Such amazingly simple logic that always seems to confound those of us whom try to sort it out...

[Guest]

can't you just say like to one of them like, what color is my shoes? and if they say the wrong one you know they're lying. Then go to the other one and say which door will lead to freedom. And vice versa...